Infinitely variable inductive remote control system



Jan. 6, 1970 w. T. CLARK I 3,488,632

INFINI'I'ELY VARIABLE INDUCTIVE REMOTE CONTROL SYSTEM Filed Feb. 20,1967 /6 Fig.

VARIABLE 22 CONTROL DEVICE INDUCTIVE FIELD 7 l8 /0 I I 35g; CONTROLLEDGENERATOR DEVICE I 24 FILTER I INPUT SIGNAL AMPLIFIER AMPLIFIER FILTERsEIIsITIvE/M GATE I I /2 m -26 28 POWER souacs;

32 L 1 Fly. 4

I4" J \4 A it I]? AMPLIFIER I 0 Will/am F Gar/r m I N VEN TOR.

United States Patent 3,488,632 INFINITELY VARIABLE INDUCTIVE REMOTECONTROL SYSTEM William T. Clark III, 400 Bayou Rapides Road, Alexandria,La. Filed Feb. 20, 1967, Ser. No. 617,325 Int. Cl. H04q N00 US. Cl.340-171 6 Claims ABSTRACT OF THE DISCLOSURE winding is within themagnetic field of the primary windv This invention relates to a controlsystem through which the supply of electrical energy to a control devicemay be infinitely varied in a reliable yet wireless manner from a remotelocation.

Remote control in accordance with the present invention is effectedthrough magnetic induction to thereby avoid the instability andsensitivity to environmental conditions associated with radio controlsystems. The system of the present invention is therefore particularlysuited for use in a confined area such as theaters in order to providean infinitely variable control over the supply of energy to controlelectrically powered devices such as lamps and electric motors. Stablecontrol by radio apparatus in such environments is impracticable becauseof spurious noises generated by other equipment such as girfconditioningand lighting instruments casing frequency ri t.

In accordance with the objects of the present invention, the supply ofelectrical energy to a powered device may be infinitely varied from aremote location by utilizing a gating device sensitive to an electricaleffect produced by varying the signal characteristic associated with theoutput of a signal generator separate and independent of the electricalpower source from which the controlled device is powered. A variablecontrol device is therefore associated with the source of signal energyfor modulation thereof in an infinitely adjustable manner to produce theelectrical effect to which the gating device responds, the signal energybeing in the form of magnetic waves within a frequency range includingfrequencies below RF values without any deliberate radiation of electricwaves.

These together with other objects and advantages which will becomesubsequently apparent reside in the details of construction andoperation as more fully in the details hereinafter described andclaimed, reference being had to the accompanying drawings forming a parthereof, wherein like numerals refer to like parts throughout, and inwhich:

FIGURE 1 diagrammatically illustrates the system of the presentinvention.

FIGURE 2 illustrates one form of gating device utilized in the system ofthe present invention.

FIGURES 3 and 4 respectively illustrate other types of gating devicescapable of being utilized in the system of the present invention.

Referring now to the drawings in detail, FIGURE 1 illustrates the remotecontrol system through which a controlled device such as a lamp or anelectric motor may be powered from a suitable source of electricalenergy 12. The supply of energy to the controlled device 3,488,632Patented Jan. 6, 1970 is controlled and regulated through a gatingdevice generally referred to by reference numeral 14 interconnectedbetween the power source and the controlled device. The gating device iscontrolled from a remote location by means of a variable control device16 which may be in the form of an infinitely variable potentiometerthrough which the output of a signal generator 18 is modulated.

The signal generator 18 produces an oscillating output at any frequencycapable of being handled by the gating device usually below radiofrequencies. One or more of the signal characteristics associated withthe oscillating output is adjustably modulated by the variable controldevice such as frequency, amplitude and phase. The signal characteristicto be modulated and its adjustment range must be selected in accordancewith the particular gating device utilized so that any variation in thesignal modula tion will produce a corresponding response in the gatingdevice to proportionately regulate the flow of electrical energy fromthe power source 12 to the: controlled device 10. Thus, the oscillatingoutput of the signal generator 18 constitutes the signal energy throughwhich input information from the variable control device 16 istransferred to the input signal sensitive gating device 14.

As shown in FIGURE 1, the output of the signal generator 18 is fed to anamplifier 20 which is impedance matched to a primary loop 22 preferablysurrounding an area within which the controlled device 10 is disposed.Disposed within the magnetic field of the primary loop 22, is asecondary inductor loop 24. The primary and secondary loops thus form arelatively large air core transformer the efiiciency of which will bedetermined by the closeness of the primary and secondary inductors. Theinductors may be made of any suitable, electrically conductive materialsuch as wire or conductive paint. Thus, the amplified oscillating outputof the signal generator 18 is transferred from the amplifier 20 to thesecondary loop 24 by magnetic induction. The oscillating outputinductively transferred by the air core transformer may be furtheramplified by another amplifier 26 impedance matched to the secondaryloop 24 in order to raise the energy level of the signal generatoroutput to a value capable of operating the gating device 14.

The signal energy fed to the gating device 14 may be transmitted througha filter device 28 placed either after the amplifier 26 as shown inFIGURE 1 or before the amplifier in order to select a predeterminedrange of signals to which the gating device will respond bydiscriminating against all other signals. The filter device may be ofany suitable type whether it be electrical, electronic or mechanical inorder to prevent passage of unwanted signals and signals intended forother controlled devices. For example, other devices may be controlledby the signal output of the same amplifier 26 through a plurality ofother filters 30 connected thereto, separating the signal output of theamplifier by differences in frequency, amplitude or phase. A pluralityof functions may therefore be performed from the variable control device16. The present invention also contemplates the disposition of aplurality of secondary inductors within the magnetic field enclosed bythe primary loop 22 in order to independently control a plurality ofcontrolled devices.

It will be apparent therefore from the foregoing, that the outputderived from the filter or amplifier, if the filter is eliminated, willcontrol the behavior of the gating device 14 in order to regulate theflow of electrical energy to the controlled device under control of thevariable control device 16. Gradual dimming of a lamp may thereby beefiected or the speed of an electric motor infinitely varied byvariation in the frequency, amplitude or phase of signal control pulsesfed to the gating device. In one form of gating device shown in FIGURE2, the amplitude of the signal pulses determines the brightness of anincandescent lam bulb 32 forming a photoresistive link with the variablephotoresistive element 34 connected in one of the power lines 36 throughwhich electrical energy is supplied from the power source to thecontrolled device 10. An amplitude responsive gating device is thereforeformed so as to regulate the amount of electrical power supplied to thecontrolled device proportionate to or as a reproducible function of theadjustment in amplitude of the oscillating output from the signalgenerator 18 by the variable control device 16.

A frequency responsive gating device 14 is shown in FIGURE 3 wherein theoutput of the amplifier or filter is fed to a frequency responsive coil38 controlling a highly compliant reed relay switch 40. The frequency ofthe signal pulses fed to the gating device 14 will determine the numberof times the switch device 40 connects the power source to the controldevice per unit time in order to statistically vary the amount of powerdelivered in proportion to or as a definite function of the frequencyvalue of the signal pulses. Other types of gating devices havingsimilarly suitable properties may also qualify such as a combinationphotoresistor link and bilateral silicon controlled rectifier circuit14" as shown in FIGURE 4. It will also be appreciated that otherproportionate controlled gating devices may be utilized involvingsaturable reactors and thyratrons.

From the foregoing description, it will be apparent that a uniquelystable, remote control system is disclosed which depends upon theresponse characteristics of a gating device to a signal effect producedat a remote location through a variable control device associated with asignal generator the output of which is transferred through magneticinduction to the gating device. The signal energy is accordinglyradiated between the inductor loops by magnetic waves only as comparedto the existence of both magnetic and electric wave radiation in radioapparatus. Signal transmission is thereby effected more reliably andwithout any detector component utilizing a gating device operative toinfinitely vary the power supplied to a controlled, power operateddevice from a power source which is independent from the source ofsignal energy through which signals are transferred to the gatingdevice.

What is claimed as new is as follows:

1. In a wireless remote control system for a controlled device poweredby a source of electrical energy, a signal generator having anoscillating output within a frequency range including signals belowradio frequencies, variable control means connected to the signalgenerator for adjustable modulating at least one signal characteristicof said oscillating output, inductive coupling means connected to saidsignal generator for transferring said oscillating output by a magneticfield only to a location remote from the variable control means whilefaithfully reproducing the modulated signal characteristic thereofcomprising an air core transformer having a primary winding and asecondary winding, means connecting the primary winding to the output ofsaid oscillator, the secondary winding being disposed in the magneticfield of said primary winding, and gate means connected to the secondarywinding and sensitive to variations in said signal characteristic forinfinitely varying the electrical energy delivered from the source tothe controlled device as a reproducible function of the adjustablemodulation of the signal characteristic by the variable control means.

2. The combination of claim 1 including filter means connected to thegate means for selecting a predetermined range of signal characteristicsto which said gate means will respond.

3. The combination of claim 2 including impedance matching amplifiersconnecting the inductive coupling means to the signal generator and thegate means for increasing the energy level of said oscillating output tooperate the gate means.

4. The combination of claim 1 wherein said gate means comprises afrequency responsive device varying the energy supplied to thecontrolled device in proportion to frequency modulation of theoscillating output by the variable control means.

5. The combination of claim 1 wherein said gate means comprises anamplitude responsive device.

6. The combination of claim 1 wherein said oscillating output of thesignal generator is-phase modulated by the variable control means.

References Cited UNITED STATES PATENTS 2,542,627 2/ 1951 Chevallier 340X 2,684,472 7/1954 Auvil 340-170 X 3,127,589 3/1964 Harris 340170 X3,137,847 6/1964 Kleist 340-170 X 3,218,638 11/1965 Honig 128-2.15

HAROLD I. PIT TS, Primary Examiner US. Cl. X.R.

l282.l5; 179-82', 325-45; 3403l0, 172

